I was advised against Costco gas by a BMW Technician. Due to the amount of detergents (either too much or too little) in the fuel and with usage over time, it can clog the injectors. For the best gas, visit http://www.toptiergas.com/retailers.html With that said, I use Shell only; same station, same pump, every time.

I was advised against Costco gas by a BMW Technician. Due to the amount of detergents (either too much or too little) in the fuel and with usage over time, it can clog the injectors. For the best gas, visit http://www.toptiergas.com/retailers.html With that said, I use Shell only; same station, same pump, every time.

hahahahahahaha !
You might want to ask yourself what they do with the extra 87 octane from the tanker truck once the underground tank is filled up and there is fuel leftover in the truck.........In goes the 87 with the 91 ......

I fill up whenever I'm at Costco and never had a problem, otherwise it is Shell for me. As for as issues with Costco gas, since I only keep my cars for about a year and put ~5K on them I doubt I'm doing any damage. But guess they are problems for the new owner.

I used to buy gas at costco once in a while because the ones that have gas station are pretty far away. They used to be quite a bit cheaper than other brand gas stations but it isn't the case anymore and I have no idea what made the change. For now, I buy chevron or shell because those two are within 30sec driving distance from where I live now.

Costco is actually a major wholesaler and refiner of gas here in Northern California. Shell, Chevron and a lot of smaller gas companies purchase gas from the Costco refinery and add their own additives to it. You see their tankers pull up to fill up at their refinery.

So whether you want to use Costco or not, you are probably pumping Costco gas into your car.

I use Chevron or 76 but I have no problem with Costco gas. I just don't have Costco membership and the lines are super long for Costco gas. I try to avoid Shell if I can.